Productivity-driven decoupling of microbial carbon use efficiency and respiration across global soils

Despite extensive research on soil microbial carbon use efficiency (CUE), its linkage to actual soil organic C dynamics remains ambiguous. A key uncertainty is that CUE estimates derived from short-term labeling incubations assume a linear negative relationship with pulse respiration rates, thereby overlooking widespread nonlinear interactions and long-term microbial acclimation in natural ecosystems. Here, we synthesized 1,094 paired observations of CUE and average annual heterotrophic respiration rate (Rh) across global natural ecosystems, and found a nonlinear relationship between them governed by ecosystem productivity. In low-productive arid and cold regions, CUE declined with increasing Rh. In contrast, in high-productivity tropical and temperate regions, CUE stabilized at a low level (0.27±0.11) as Rh exceeded a threshold of 340±10.8 g C m-2 y-1. This shift reflects a fundamental microbial trade-off between C assimilation and the maintenance of stoichiometric homeostasis.
, , # Productivity-driven decoupling of microbial carbon use efficiency and respiration across global soils

Dataset DOI: [10.5061/dryad.8cz8w9h49](https://doi.org/10.5061/dryad.8cz8w9h49)

## Description of the data and file structure

The dataset (Raw_Data.csv) include 1094 pried observations of CUEst and Rh, as well as other environmental variables (Soil_MAT, MAP, LAI, and Soil_pH).

| Variables | Full name | Unit |
| :-------------- | :------------------------------------------------------ | :---------- |
| Paper\_ID | Unique number of publication | - |
| Climatic\_Group | global Köppen-Geiger classification of climate | - |
| Soil\_MAT | Soil mean annual temperature | ℃ |
| MAP | Mean annual precipitation | mm |
| LAI | Leaf area index ...,

尽管学界已对土壤微生物碳利用效率（soil microbial carbon use efficiency, CUE）开展了大量研究，但其与实际土壤有机碳动态的关联仍不甚明晰。核心不确定性在于：基于短期标记培养得到的CUE估算值，均假设其与脉冲呼吸速率呈线性负相关关系，因而忽略了自然生态系统中广泛存在的非线性相互作用与长期微生物驯化过程。
本研究整合了全球自然生态系统中1094组CUE与年均异养呼吸速率（heterotrophic respiration rate, Rh）的配对观测数据，发现二者间的非线性关系由生态系统生产力所调控。在低生产力的干旱与寒冷区域，CUE随Rh升高而降低；与之相反，在高生产力的热带与温带区域，当Rh超过340±10.8 g C m⁻² y⁻¹阈值后，CUE会稳定维持在较低水平（0.27±0.11）。这一转变反映了微生物在碳同化与维持化学计量内稳态之间存在根本性的权衡关系。

# 全球土壤微生物碳利用效率与呼吸作用的生产力驱动解耦

数据集DOI: [10.5061/dryad.8cz8w9h49](https://doi.org/10.5061/dryad.8cz8w9h49)

## 数据与文件结构说明
本数据集（Raw_Data.csv）包含1094组CUEst与Rh的配对观测数据，以及其他环境变量：土壤年均温（Soil_MAT）、年均降水量（MAP）、叶面积指数（LAI）与土壤pH（Soil_pH）。

| 变量名 | 中文全称 | 单位 |
| :-------------- | :------------------------------------------------------ | :---------- |
| Paper_ID | 文献唯一编号 | - |
| Climatic_Group | 全球柯本-盖格（Köppen-Geiger）气候分类类型 | - |
| Soil_MAT | 土壤年均温 | ℃ |
| MAP | 年均降水量 | mm |
| LAI | 叶面积指数 | ... |